1. Field of the Invention
The invention herein disclosed generally relates to semiconductor processing systems, and specifically relates to vacuum semiconductor processing work piece handling and transportation.
2. Description of the Related Art
Current semiconductor manufacturing equipment takes several different forms, each of which has significant drawbacks. Cluster tools, machines that arrange a group of semiconductor processing modules in a radius about a central robotic arm, take up a large amount of space, are relatively slow, and, by virtue of their architecture, are limited to a small number of semiconductor process modules, typically a maximum of about five or six. Linear tools, while offering much greater flexibility and the potential for greater speed than cluster tools, do not fit well with the current infrastructure of most current semiconductor fabrication facilities. Moreover, linear motion of equipment components within the typical vacuum environment of semiconductor manufacturing leads to problems in current linear systems, such as unacceptable levels of particles that are generated by friction among components. Several hybrid architectures exist that use a combination of a radial process module arrangement and a linear arrangement.
As semiconductor manufacturing has grown in complexity, it becomes increasingly necessary to transfer wafers among a number of different process modules or clusters of process modules, and sometimes between tools and modules that are separated by significant distances. This poses numerous difficulties, particularly when wafers are transferred between separate vacuum processing facilities. Transfers between vacuum environments, or between a vacuum and other processing environments often results in increased risk of particle contamination (due to the pumping and venting of wafers in load locks) as well as higher thermal budgets where wafers are either heated or cooled during transfers.
There remains a need for improved wafer transport and handling system for use in semiconductor manufacturing environments.